The method for preparing rhenium plates includes the following steps: 1, preparing a vacuum electron beam melting electrode; 2, subjecting the melting electrode obtained in step 1 to two vacuum electron beam melting processes to obtain a pure rhenium metal ingot; 3, grinding the pure rhenium metal ingot obtained in step 2 and then wire-cutting it to obtain a rhenium sheet; 4, rolling the rhenium sheet obtained in step 3 to obtain a rhenium plate of the required specifications. In this method, the pure rhenium sintered billet is used as the vacuum electron beam melting electrode for two vacuum electron beam melting processes, resulting in a rhenium plate with a purity ≥99.99%, a density reaching the theoretical density of 21.04 g/cm³, and a material utilization rate (weight after melting/weight of raw material) exceeding 98%.
A method for preparing pure rhenium plates involves using pure rhenium powder with a purity ≥99.99% as raw material. The material is densified using hot isostatic pressing (HIP), and the pure rhenium plates are obtained through cold deformation rolling. During HIP, the powder needs to be clad, resulting in significant rhenium loss during cladding removal. Since rhenium is expensive, the cost per furnace for HIP is also very high. A method for manufacturing pure rhenium products includes rhenium powder pretreatment, pressing, dewaxing, pre-sintering, cladding, HIP, decladding, and high-temperature sintering to produce large-sized pure rhenium rods and blocks. A method for manufacturing ultrathin high-purity rhenium foil includes spheroidizing high-purity rhenium powder, rolling a compact using a powder mill, and preparing rhenium foil through high-temperature sintering, continuous rolling, and annealing.
Conventional rhenium metal products are typically manufactured using powder metallurgy. As seen in the patents listed above, high-purity rhenium products are obtained using high-purity raw material powders, but the manufacturing process has almost no purification effect on the material. Furthermore, conventional powder metallurgy cannot produce dense rhenium billets; densification can only be achieved through external forces such as hot isostatic pressing and deformation processing, but even these methods cannot reach the theoretical density of metallic rhenium, generally only achieving about 98% of the theoretical density.
The method for preparing rhenium plates yields rhenium plates with a purity ≥99.99% and a density reaching the theoretical density of 21.04 g/cm³. To achieve the above objectives, the present invention provides the following technical solution: A method for preparing a rhenium plate, comprising the following steps:
1. Preparing a vacuum electron beam melting electrode;
2. Performing two vacuum electron beam melting processes on the melting electrode obtained in step 1 to obtain a pure rhenium metal ingot;
3. Grinding the pure rhenium metal ingot obtained in step 2 and then wire cutting it to obtain a rhenium sheet;
4. Rolling the rhenium sheet obtained in step 3 to obtain a rhenium plate of the required specifications.
Furthermore, in step 1, the preparation of the vacuum electron beam melting electrode specifically includes the following steps:
1-1. Loading rhenium metal powder with a purity ≥99% into a mold for pressing and forming to obtain a pure rhenium billet;
1-2. Sintering the pure rhenium billet at high temperature to obtain a pre-densified pure rhenium sintered billet, wherein the pure rhenium sintered billet is the vacuum electron beam melting electrode.
Further, in step 1-1, the pressing and forming process is cold isostatic pressing, with a forming pressure of 60-100 MPa and a forming time of 3-5 min;
and/or, in step 1-1, the rhenium metal powder is vibrated and compacted before the cold isostatic pressing process, with a vibration frequency of 40-80 times/min.
Further, in step S1-2, the high-temperature sintering temperature is 2000-2300℃, and the sintering time is 4-8 h;
and/or, sintering is carried out in a hydrogen atmosphere or a vacuum atmosphere;
and/or, in step S1-2, the density of the obtained pure rhenium sintered billet is 18-20 g/cm³;
and/or, the diameter of the vacuum electron beam melting electrode is 20-100 mm, and the length is ≥200 mm.
Further, in step S2, the first vacuum melting speed is 50–70 kg/h, and the second vacuum melting speed is 20–30 kg/h;
and/or, the melting power is 160–200 kW, and the melting vacuum degree is ≥5 × 10⁻³ Pa;
and/or, the density of the pure rhenium metal ingot obtained in step S2 reaches the theoretical density of 21.04 g/cm³.
Further, in step S3, the grinding method includes grinding with a grinding wheel or machining on a lathe.
Further, in step S4, the rolling process specifically includes multi-pass cold rolling of the rhenium sheet at room temperature, and the rolled billet undergoes at least two annealing treatments during the multi-pass cold rolling deformation process.
Further, in step S4, the deformation amount per rolling pass is ≤20%;
and/or, in step S4, the annealing temperature is 1300–1800 °C, and the annealing time is 1–2 h.
In addition, the present invention also provides a rhenium plate, which is manufactured by the above-described method for preparing rhenium plates.
Furthermore, the purity of the rhenium plate is ≥99.99%, and its density is 21.04 g/cm³.
Compared with the prior art, the technical solution of the present invention has at least the following technical effects: In the method for preparing the rhenium plate of the present invention, the obtained pure rhenium sintered billet is used as a vacuum electron beam melting electrode for two vacuum electron beam melting processes. The final rhenium plate has a purity ≥99.99%, a density reaching the theoretical density of 21.04 g/cm³, and a material utilization rate (weight after melting/weight of raw material) that can reach over 98%.
